Λ-p femtoscopy in collisions of Ar+KCl at 1.76AGeV

Abstract

Results on Λp femtoscopy are reported at the lowest energy so far. At a beam energy of 1.76AGeV, the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. A high-statistics and high-purity Λ sample was collected, allowing for the investigation of Λp correlations at low relative momenta. The experimental correlation function is compared to corresponding model calculations allowing the determination of the space-time extent of the Λp emission source. The Λp source radius is found to be slightly smaller than the pp correlation radius for a similar collision system. The present Λp radius is significantly smaller than that found for Au+Au/Pb+Pb collisions in the AGS, SPS, and RHIC energy domains but larger than that observed for electroproduction from He. Taking into account all available data, we find the Λp source radius to increase almost linearly with the number of participants to the power of one-third. © 2010 The American Physical Society.